People that complain that Ash should be gone cough SatoSere cough fail to realize one thing: That VA have deep relationship with the characters that they have been voice acting for more that a decade. It hard to "throw" that away. It easy for us as a viewer to claim that "Oh Ash is stale, he should leave bah bah. " It hard for them who have been voicing the character for more than a decade to say goodbye (Like Rica and Ash)
To Rica, Ash is probably her greatest achievement, just like Jason Frank whose greatest achievement is being the Power Ranger. Wanting Ash to leave after everything that he have achieve from the viewer who complain that the anime is NOT TARGETED to (demo and countries wise), is a slap to her face by saying "Oh, thank for your contribution, but you can leave now since people wanting Ash to leave cough SatoSere cough dont want to hear you anymore" This is just like asking Peter Cullen to stop voicing Optimus Prime or Tom Kenny to stop voicing Spongebob because the character is stale and their voice doesn't " match" with the character
If Ash come back again for Gen 9 anime, you can don't watch, no one is forcing people that wanted Ash to leave to watch and then complain again on why Ash is still in the anime as the protagonist